Hydraulic transmission for tumble-type fabric treating machines

ABSTRACT

A FABRIC TREATING MACHINE OF THE TUMBLE-TYPE, INCLUDING A FABRIC CONTAINER DISPOSED AT AN ANGLE TO THE VERTICAL AND A HYDRAULIC TRANSMISSION DRIVINGLY CONNECTED TO THE FABRIC CONTAINER. SPEED CONTROL MEANS AND DUAL RANGE FLOW CONTROL MEANS ARE INCORPORATED IN THE TRANSMISSION AND OPERATE TO SELECTIVELY VARY THE CONTAINER SPEED WITHIN PREDETERMINED SETTINGS FOR BOTH A LOW SPEED &#34;TUMBLE&#34; RANGE OF OPERATION AND HIGH SPEED CENTRIFUGAL-EXTRACTION RANGE OF OPERATION.

March 2, 1971 McAN|NcH ETAL HYDRAULIC TRANSMISSION FOR TUMBLE-TYIE FABRIC TREATING MACHINES Filed June 30, 1969 Pm 1 n N Nw 9 WIIFI. m8 IIIIIIL r Q 1035 26m 9 9.

III

1 N v E N TO 25 HERBERTAMM/W/VC/I HIFPEERT M U/VflfPWOOD BY PM! ATTOQNE3 United. States Patent Ofice 3,566,627 Patented Mar. 2, 1971 3,566,627 HYDRAULIC TRANSMISSION FOR TUMBLE- TYPE FABRIC TREATING MACHINES Herbert A. McAninch, Auburn, Ind., and Herbert N.

Underwood, Chicago, Ill., assignors to Borg-Warner Corporation, Chicago, Ill.

Filed June 30, 1969, Ser. No. 837,702 Int. Cl. D06f 21/10, 37/36 U.S. C]. 68-24 4 Claims ABSTRACT OF THE DISCLOSURE SUMMARY OF THE INVENTION This invention relates to fabric treating machines, and more particularly to fabric treating machines of the tumble-type incorporating a hydraulic transmission to drive a fabric container disposed at an angle to the vertical.

Tumble-type washing machines known in the art have generally been driven by electric motors through mechanical reduction gears. This construction involved belts, gears, shafts and the like, which presented considerable difliculty in maintaining accurate alignment. Another inherent difliculty in such prior art devices was the problem of noisy operation.

One approach which has been developed for fabric treating machines of the horizontal axis type is to use a hydraulically powered reversing cylinder for wash action and a hydraulic powered wringer for drying the clothing.

An improvement over this design was the approach taken by Wilcox and shown in U.S. Patent No. 2,582,810. The fabric treating machine there illustrated is of the horizontal axis type and uses a hydraulic transmission to reverse the direction of rotation of the fabric container for washing action and to rotate the fabric container at high speed in a single direction for centrifugal extraction.

The present invention is directed to providing a fabric treating machine combining the inherent advantages of a hydraulic transmission with the inherent advantages of a tumble-type machine. The present invention is particularly directed to providing a hydraulic transmission adapted to rotate the fabric container in a single direction for both a low speed wash and a high speed centrifugal extraction. This transmission is further adapted to allow the operator to vary the rotational speed between predetermined limits in both of the speed ranges.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a hydraulic transmission for a tumble-type clothes washer during the spin cycle embodying the principles of the invention.

FIG. 2 is a section view taken along the line 22 in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a fabric treating machine in the form of a washing machine is illustrated comprising a tub 10 adapted to hold a laundering fluid and a clothes container 11, both tilted at an angle to the vertical, here illustrated as roughly 60 A hydraulic transmission 12 is illustrated for driving the clothes container 11 in a single direction of rotation to effect either a low speed washing operation or a high speed centrifugal extraction operation. The transmission 12 includes a transmission inner housing generally designated as 13.

An electric motor 15 is provided having a water pump 16 driven thereby for recirculating the water in the clothes container 11 of the automatic washer during the wash operation. The source of power 18 is illustrated for operating the motor 15. The cycle selector switch 19 is schematically illustrated in simplified form, although in a washer installation, this function would be performed by a timer switch mechanism of known construction. Electric leads 21 and 24 inter-connect the source of power 18 with the motor 15. Leads 22 is provided to connect the motor 15 to ground. Lead 23 connects the source of power 18 to switch mechanism 19.

The electric motor 15 includes a rotatable drive member 27 which connects the motor to a hydraulic pump 28. The hydraulic pump 28 includes a pumping element 29 and a fixed pump housing element 30. The tub 10 is attached to the fixed housing 30, as indicated by dotted lines 33 and 34.

Any of a number of well-known types of hydraulic pumps would adequately perform the function of the hydraulic pump 28, as for example, the crescent type or the gerotor type, but for reasons that will be later described, it is found that the vane type pump will perform best in the present transmission. For this reason, the hydraulic pump 28 is illustrated as a vane pump.

The pumping element 29 consists of a rotor 36 connected to the rotatable drive member 27 of the electric motor 15. The rotor 36 contains a series of radial slots 37. A plurality of vanes 38 are provided, each vane adapted to slide within a slot 37.

The rotatable pump housing element 30 consists of an annular disc mounted eccentric to the rotor 36. A pair of arcuate ports 39 and 41 are formed in the pump housing element 30. The port 41 is an inlet port and the port 39 is an exhaust port. A fluid sump 42 is schematically illustrated for convenience at various places in the illustration of the invention, although in the actual construction one fluid sump 42 is provided into which all of the exhaust connections for various elements of the transmission exhaust fluid.

Through rotation of the pumping element 29 in a clockwise direction as viewed in FIG. 1, a hydraulic circuit is established. A fluid conduit 44 is provided to communicate fluid from the sump 42 to port 41 when the hydraulic circuit is established. A fluid conduit 46 is provided to conduct fluid from the port 39 to a dual range flow control valve 47. A conduit 48 is provided to communicate fluid from the conduit 46 to the upstream end of a bypass valve 49. A fluid conduit 51 is provided to communicate fluid from the dual range flow control valve 47 to a rotary hydraulic motor 52. A fluid conduit 53 is provided to communicate fluid from the rotary hydraulic motor 52 to sump 42. A fluid conduit 54 is provided to connect conduit 51 with the downstream side of the bypass valve 49. A pilot pressure relief valve 56 is connected to the downstream side of the by-pass valve 49.

The dual range flow control valve 47 comprises a housing 57 defining a pair of bores 58 and 59. The housing 57 further defines a pair of annular peripheral reliefs 61 and 62. A valve member 63 is adapted to slide axially within the bore 58 and has a tapered section 64 including a small end 66 and a large end 67. A cylindrical rod 68 concentric with the valve member 63 extends from the small end 66 of the tapered section 64 outside of the housing 13. Immediately adjacent the large end 67 is a pilot section 70 of essentially the same diameter as large end 67 As shown in FIG. 2, a pair of grooves 71 and 72 are provided in the pilot section 70. The tapered section 64 coacts with an edge 73 to define a variable orifice through which fluid is communicated to the outlet of the dual range flow control valve 47. A spring 76 acts against the end of the pilot section to bias the valve member 63 down and to the left as shown in FIG. 1. Associated with the dual range flow control valve 47 is an electric actuator 77 here shown as an electrical solenoid. The solenoid 77 is operative to shift the valve against the force of a spring 78 positioned within the housing 13. The solenoid 77 is connected to the wash terminal of the cycle selector switch 19 by an electrical lead '80. The solenoid is also connected to line 21 by means of an electrical lead 81.

A speed control mechanism 87 is provided to vary the position of the valve member 63 with respect to the housing 57 and thereby vary the area of the orifice controlling the volume of fluid flowing through the dual range flow control valve. This orifice will hereafter be referred to as the control orifice. The speed control mechanism 87 includes a control lever 88 suitably attached to cam 89 and adapted to rotate the cam according to a setting of the control lever 88. A lever arm 90 is provided pivoted about an axis 91 having an end 92 biased to contact cam 89 by a spring 94. The outer end 95 of lever arm 90 is adapted to contact the cylindrical rod 68 and thereby selectively vary the position of valve 63 with respect to the housing 57 in response to positioning of the control lever '88.

The by-pass valve 49 includes a valve member 96 acting within a bore 97 defined by the housing 13. An annular chamber 98 in the bore 97 co-acts with an edge 99 of the spool valve 96 to define a variable orifice in fluid communication with the sump 42. The valve member 96 has an end face 101 against which fluid pressure in the upstream end acts and an end face 103 against which fluid pressure in the downstream end acts. A spring 104 is provided in the downstream end of bore 97 to urge the valve member 96 toward the upstream end of bore 97.

The pilot relief valve 56 is provided in communication with bore 97 to serve as a safety valve by connecting the bore 97 to sump in case of extreme pressure build-up in the agitator motor supply conduit 51.

The rotary hydraulic motor 52 is shown in FIG. 1 as being of the gerotor type although other fluid motors could also be used. The rotary motor 52 includes an outer rotor 105 and an inner rotor 106. The inner rotor 106 is connected to the clothes container 11 by means of a shaft 107. Fluid pressure is admitted to the motor during both the Wash cycle and the fluid extraction cycle from conduit 51 and in a known manner will act in the fluid chambers between the teeth of the inner rotor and the recesses of the outer rotor to spin the inner rotor and the clothes container attached thereto. Conduit 53 is the exhaust fluid connection for the rotary hydraulic motor 52.

The operation of the fabric treating machine as shown in l and previously described herein, is as follows: The timer or cycle selector switch of the automatic Washer schematically represented by switch 19 will first select the Wash cycle for the hydraulic transmission. The electric motor 15 will be activated to rotate in a clockwise direction as viewed from the top in FIG. 1. The pumping element 29 will also rotate, its speed of rotation correspondto the speed of rotation of the rotatable drive member After the first revolution of the pumping element 29, the vanes 38 will be disposed within their corresponding slots 37 out of contact with the pump housing element 30, effecting a zero output of the pump 28, since no pumping action is taking place. At a predetermined rotational speed the vanes will be urged to move radially outward by centrifugal force to contact the pump housing element 30 thereby initiating a pumping action. The desired rotational speed at which pumping becomes effective can be achieved by properly designing the geometry of the rotor 4 and vanes. The obvious result of using this particular type of hydraulic pump is that it enables the electric motor to build up suflicient speed before imposing a load on it.

Since the wash cycle has first been selected, the dual range flow control valve 47 will be actuated by the solenoid 77 and moved to the solid line position shown in FIG. 1. The solenoid 77 is actuated through its contact with the wash terminal of the cycle selector switch 19 and urges the dual range flow control valve 47 to move to the solid line position against the force of the spring 78. As should be apparent from the drawings and from the description, the variable control orifice which is established between the valve member 63 and the edge 73 of the peripheral relief 62 will be relatively small when the flow control valve is in the solid line position as illustrated in FIG. 1. When the spin cycle is selected and the solenoid 77 is deactivated, the spring 78 will urge the dual range flow control valve 47 to the dotted line position shown in FIG. 1. In this position a relatively large control orifice will be established between the valve member 63 and the edge 73 of the peripheral relief 62.

As the pumping element 29 rotates in a clockwise direction, fluid will be drawn from the sump 42 into conduit 44 and communicated to the inlet 41 of the hydraulic pump 28. As the fluid is pressurized, it will be delivered from the outlet port 39 to conduit 46 and from there will enter the dual range flow control valve which is now positioned in its solid line position. The position of cam 89 will determine the size of the variable orifice in this the low speed range.

Fluid leaves the dual range flow control valve 47 by a conduit 51 at a pressure lower than the pressure of the fluid which enters the valve in accordance with the principle Well-known in the art, whereby a pressure drop will result when fluid flows through a control orifice.

Fluid leaving the dual range flow control valve 47 is communicated to the rotary hydraulic motor 52 through conduit 51 to drive the clothes container 11 of the washing machine.

In the absence of by-pass valve 49, it would be obvious that the variation in size of the control orifice would have little effect on the speed of the rotary hydraulic motor 52. The speed of the rotary hydraulic motor 52 is directly proportional to the volume of fluid supplied to it per unit time. Using a constant displacement pump, the effect of reducing the size of the control orifice would be to increase the average velocity of fluid across the orifice, the volume flow per unit time remaining essentially unchanged.

Fluid pressure is admitted to the upstream end of bore 97 from conduit 48 to act against end face 101 of the valve member 96 to urge the valve member 96 upwardly allowing some of the fluid in the upstream end of bore 97 to escape to sump. It is evident from FIG. 1 that the pressure of fluid supplied to the upstream end is substantially the same as the pressure of the fluid supplied to the control orifice.

Fluid at the lower pressure is admitted to the downstream end of bore 97 from conduit 54 to act against the end face 103 of the valve member 96 which has the same area as end face 101. This force acts in cooperation with the force of the spring 104 to bias the valve member 96 to the bottom of the bore 97 thereby restricting the flow of fluid from the upstream end to sump 42.

It can now be seen that the characteristics of the spring 104 and the cross sectional area of by-pass valve 96 determine the value of the pressure drop across the control orifice. The pressure drop for any given size orifice is dependent upon the volume of fluid passed through the orifice per unit time. As the volume flow through the orifice increases, the resulting pressure drop across the orifice will also increase, The converse is also true.

If for a range of orifice size, the desired pressure drop is, for example, 10 p.s.i. a spring will be chosen with characteristics such that it will exert a force equal to that exerted by a pressure of p.s.i. against the area of end face 101 of valve member 96. It is understood, of course, that the variation of spring force due to compression of the spring is negligible due to the small displacements involved and a low spring constant. For the by-pass valve to open, the pressure of the fluid entering the upstream end of bore 97 must exceed the pressure of the fluid entering the downstream end by at least 10 p.s.i. If the pressure differential, hence the pressure drop across the control orifice, is greater than 10 p.s.i., the by-pass valve will open wider allowing a greater volume of fluid to be by-passed to sump. The volume of fluid through, hence the pressure drop across, the control orifice will therefore be reduced until the pressure differential equals 10 p.s.i. at which point the system will be at equilibrium.

If the pressure differential is less than 10 p.s.i., the spring force of the pressure force on end face 103 of the valve member 96 will exceed the force on the end face 101, causing the valve member 96 to close until the pressure differential reaches equilibrium at 10 p.s.i. Thus, it has been shown that with the selection of the proper spring, the pressure drop across the control orifice can be held at the same predetermined value over a range of orifice sizes. Making use of this principle, it has further been shown that by varying the size of the control orifice, which is accomplished by varying the orientation of the cam 89, the volume of fluid per unit time passing through the control orifice and delivered to the rotary hydraulic motor 52 may be varied, the speed of the clothes container increasing as the flow increases.

When the timer for the cycle selector switch advances from the wash to the spin position, the solenoid 77 will become deenergized and the spring 78 will urge the dual range flow control valve 47 to the dotted line position, as shown in FIG. 1. The control orifice which is now established between the valve member 63 and the edge 73 of the peripheral relief 62 is now substantially larger than the control orifice previously described for the wash operation. As a result of the substantially increased control orifice, a substantially greater volume of fluid per unit time is communicated to the rotary hydraulic motor 52 and, consequently, the motor 52 is spun at a substantially greater speed as is the clothes container 11.

The operation of the fabric treating machine in the spin cycle of operation is substantially the same as in the wash operation previously described. The speed of the clothes container 11 is determined by the speed control mechanism 87 in conjunction With the setting of the cam 89. Any movement of the cam 89 which would move the valve member 63 to increase the orifice size would result in a corresponding increase in the rotation speed of the fabric container 11.

Various of the features of the invention have been particularly shown and described, however, it should be obvious to one skilled in the art that various modifications may be made therein without departing from the scope of the invention.

What is claimed is:

1. A fabric treating machine adapted to perform a washing operation and a centrifugal extraction operation including a fabric container having a central axis disposed at an angle to the vertical; a rotary hydraulic motor Operatively associated with said fabric container; a hydraulic pump in fluid communication with said hydraulic motor; drive means connected to said hydraulic pump; dual range flow control means disposed between said hydraulic pump and said hydraulic motor to control the flow of fluid from said pump to said motor, said fiow control means positionable in either a low speed setting operative to effect a relatively low speed tumbling operation or a high speed setting operative to effect a relatively high speed centrifugal extraction operation; speed control means associated with said dual range flow control means operative to selectively vary the flow of fluid from said pum to said motor in either the low or high speed setting thereby varying the speed of rotation of said container over predetermined ranges in both the high and low speed settings.

2. A fabric treating machine as in claim 1 including an electrical actuator operatively associated with said dual range flow control means, said actuator operative to change the position of said flow control means from one setting to another.

3. A hydraulic transmission for a fabric treating machine having a fabric container tilted at an angle to the vertical and adapted to perform a tumble washing operation and a centrifugal extraction operation, said hydraulic transmission including a hydraulic pump; drive means connected to said hydraulic pump; a rotary hydraulic motor associated with said hydraulic pump and drivingly connected to said fabric container, said hydraulic motor adapted to be driven by said hydraulic pump; dual range flow control means disposed between said hydraulic pump and said hydraulic motor to control the flow of fluid from said pump to said motor, said flow control means positionable in either a low speed setting operative to effect a realtively low speed tumbling operation or a high speed setting operative to effect a relatively high speed centrifugal extraction operation; speed control means associated with said dual range flow control means operative to selectively vary the flow of fluid from said pump to said motor in either the low or high speed setting thereby varying the speed of rotation of said container over predetermined ranges in both the high and low speed settings.

4. A hydraulic transmission for a fabric treating machine as in claim 3 including an electrical actuator operatively associated with said dual range flow control means, said actuator operative to change the position of said flow control means from one setting to another.

References Cited UNITED STATES PATENTS 2,582,810 1/1952 Wilcox 6824X 2,807,963 10/1957 Osterhus et al. 6824X 3,443,381 5/1969 Underwood et al 60-53 3,443,405 5/ 1969 McAninich et a1. 1 60-53X PRICE C. FAW, 111., Primary Examiner US. Cl. X.R. 60-53 

